It is known to produce fire resistant fabrics for use as mattress tickings, bedspreads and the like by using yarn formed of natural or synthetic fibers and then treating the fabric with fire retarding chemicals, such as halogen-based and/or phosphorus-based chemicals. This type of fabric is heavier than similar types of non-fire retardant fabrics, and has a limited wear life. Also, this type of fabric typically melts or forms brittle chars which break away when the fabric is burned.
It is also known to form fire resistant fabrics of fire resistant relatively heavy weight yarns in which a low temperature resistant fiber is ring spun around a core of continuous filament fiberglass. However, this type of ring spun yarn has torque imparted thereto during the spinning process and is very lively. Because of the lively nature of the yarn, it is necessary to ply "S" and "Z" ring spun yarns together so that the torque and liveliness in the yarn is balanced in order to satisfactorily weave or knit the yarn into the fabric, without experiencing problems of tangles occurring in the yarn during the knitting or weaving process. This plying of the "S" and "Z" yarns together results in a composite yarn which is so large that it cannot be used in the formation of fine textured, lightweight fabrics. In some instances the fiberglass filaments in the core protrude through the natural fiber sheath. It is believed that the problem of protruding core fibers is associated with the twist, torque and liveliness being imparted to the fiberglass core during the ring spinning process.
It is the current practice to produce coated upholstery fabrics by weaving or knitting a substrate or scrim of a cotton or cotton and polyester blend yarn. This scrim is then coated with a layered structure of thermoplastic polyvinyl halide composition, such as PVC. This coated upholstery fabric has very little, if any, fire resistance and no flame barrier properties.